If you have an infestation of Japanese Beetles and you want to get rid of them, you’ve come to the right place.
In this guide you'll learn:
- What attracts Japanese Beetles?
- How to get Japanese Beetles out of your house.
- How to get Japanese Beetles out of your yard.
- How to prevent Japanese Beetles in the first place
- Our suggestions for the best products to get rid of Japanese Beetles.
Keep on reading and we’ll walk you through everything you need to know! But if you're short on time, click here to jump to our suggestions for getting rid of Japanese Beetles.
What Attracts Japanese Beetles in the First Place?
Adult Japanese beetles are drawn to over 300 different types of plants. They feed on the leaves, fruits, and flowers of apple trees, basil, birch, cherry, crabapple, elm, hollyhock, marigold, rose bush, raspberries, soybean, and others.
The beetle damage is easy to identify. The adult beetles attack in swarms and eat away all the parts of the leaves except for the veins, creating a “skeletonized” appearance that is quite distinctive. These garden pests mainly attack in the early morning.
Japanese beetle larvae, also known as white grubs, live in the soil. The mated female beetles will dig 2-3 inches into damp soil to lay eggs, usually 40-60 at a time. They can lay several batches of eggs during their 1-2 month lifespan.
When the Japanese beetle grubs hatch, they begin feeding on the roots of nearby plants, primarily turf grasses of various kinds. In the grub stage, they are completely subterranean. The only way you’ll know you have them is when brown spots appear on your lawn because they have been eating grass roots.
During the winter they burrow deep underground and stay there until the ground warms up the next year in the spring. Then they begin eating again until they enter the pupal stage, emerging from the ground a few weeks later as adult beetles to start the whole process all over again.
So, what attracts Japanese beetles? Pretty much everything in your yard and garden. Almost any plant or tree attracts them. That being the case, how do you control a Japanese beetle infestation?
Pest control is the art and science of finding methods to kill or repel invading insect populations, such as a beetle population, and applying them in a careful, methodical manner until the problem is solved. So, let’s get to it.
Read More: How to Kill and Get Rid of Carpet Beetles
4 Natural Remedies to Quickly Get Rid of Japanese Beetles From Inside Your House
Japanese beetles aren’t normally an inside pest, but if the population grows too much, some of them could wind up in your house by accident. When that happens, you need to be able to get rid of them.
Diatomaceous earth is made from the fossilized bodies of tiny, almost microscopic organisms called diatoms. Their silica shells have razor-sharp edges. A 10-pound bag of food-grade diatomaceous earth is more than enough to use against Japanese beetles.
Sprinkle a fine layer of it all around the windows and door thresholds. Also, sprinkle it around the areas where you see them landing and crawling around. As they come into contact with it, it kills them by one of two different modes of action.
In the first mode, the dryness of the diatomaceous earth absorbs moisture from the bodies of the insects crawling across it. Japanese beetles are so small that the loss of moisture can be lethal. Unless they find water very quickly, they will die.
The second mode is related to the first. The sharp edges of the diatoms cut the shells of the beetles as they crawl over them. This speeds up the process of dehydration, killing them even quicker than dehydration alone.
The best part of this method is that it is completely safe, even around children and pets. The next best thing is that it lasts for as long as the diatomaceous earth is there. Unless it gets wet, it could last for months at a time.
Read More: Diatomaceous Earth
2. Neem Oil
Neem trees are found in Asia and the oil from them has been used for hundreds of years for pest control against insects of all kinds. It is a yellowish-brown color with a slightly bitter taste, and a garlic or sulfurous smell to it.
Neem oil interferes with the hormone system in insects, making it difficult for them to reproduce. It also reduces their feeding and acts as a repellent, pushing insects away from areas treated with it.
Pre-bottled Neem oil is available in a 32-ounce spray bottle that is ready to be used without any mixing required. Due to its repellent properties, this is a good product to spray around the edges of windows and doors, the primary entry point for beetles and insects of all kinds.
You should also spray it on any plants you have in the house to keep Japanese beetles from feeding on them. It’s 100% natural and can be used without it hurting your children or pets.
Read More: Neem Oil Facts, Unpacked
One of the more interesting methods of getting rid of Japanese beetles in your house is to use geraniums against them.
Researchers have discovered that geraniums poison Japanese beetles when they feed on them. After feeding on geraniums, Japanese beetles are paralyzed or killed. While some of them do recover after a time, many of them don’t. In either case, they can be picked up and killed before any recovery can take place.
This gives you a nice two-for-one way of killing Japanese beetles.
- The first method is to buy geranium seeds and plant them in small pots around the house. Not only will you have some beautiful plants in the house, but they’ll also be a completely natural method of Japanese beetle control.
- The second method is to buy geranium oil, mix 6 drops of it with 1/2 cup of water and put it in a spray bottle. Spray all the entrances to the house, paying special attention to the cracks and crevices around the windows and doors.
Whichever method you decide to use, you’ll have to sweep up the dead and dying ones on the floor. You might also have to do some hand picking to get any on the leaves or petals of the plants.
The video below offers an in-depth look at how to get rid of Japanese Beetles.
3 Additional Remedies to Get Rid of Japanese Beetles From Inside Your House Fast
Natural remedies have the advantage of being completely safe for use around children and pets. The disadvantage to them is that they’re generally slower and less consistent than artificial methods such as using pesticides.
Let’s take a quick look then at some pesticides that are labeled for Japanese beetles.
Suspend is a long-standing favorite in the pest control industry. Pest control technicians, including many of us here at Pest Strategies, have successfully used Suspend for many years to eradicate bugs of all kinds.
The active ingredient is called Deltamethrin. It does a good job of killing many different kinds of beetles, including Japanese beetles. It requires you have a 1-gallon pump-up spray canister. Mix it with water according to the directions on the label and mix it thoroughly.
To prevent Japanese beetles, mix it at the lower rate of 0.03%. If you already have Japanese beetles in the house and you want to kill them fast, mix it at the higher rate of 0.06%. This is called the clean-out rate.
Spray it around the baseboards, windows, and doors throughout the entire house. You can also spray it up in the corners to kill spiders.
Suspend, like all pesticides, is heavily regulated by the EPA. As such it is required by law to biodegrade down to zero within 90 days, at which point it will be gone. This means you’ll have to reapply it every three months.
Contrary to popular opinion, modern insecticides are extremely safe. However, many insecticides are hazardous to fish and birds. If you have fish or birds in your house, cover the aquarium and birdcage before you start spraying. After you’re finished spraying, wait 20-30 minutes before uncovering them.
Another Deltamethrin-based insecticide is Delta Dust. It’s a very fine powder, similar to baby powder or talcum powder. To use it, you need to get a bulb duster, also known as a puffer duster.
Fill the duster to the halfway mark with dust, then turn it over so the thin rod is on top. Shake it vigorously a time or two to create a cloud of dust inside it. Then give it a quick squeeze and a faint cloud of dust will be ejected from the tip of the rod.
NOTE: from years of experience using dusters, we recommend putting a marble or a nickel into the duster. Having it bounce around inside helps stir up the dust, which tends to clump.
Don’t puff a cloud of dust into the open air. Instead, use it to coat the inside of tiny cracks and crevices around the windows, doors, fireplace, vents, baseboards, and such. Those little cracks and crevices represent a major highway for bugs to enter your house.
Put the tip of the rod next to the crack or crevice and give it a sharp squeeze. The dust will puff into the opening and completely cover all the surfaces inside it. The Japanese beetles coming through there will come into contact with it and die.
Glue boards or insect monitors are another way of killing bugs. They’re a broad-spectrum approach. The sticky glue on them will catch any bug that comes in contact with it, so you’ll catch a lot more than just Japanese beetles.
These glue boards can be laid out flat or folded into a triangular shape. They work in either configuration. They’re extremely cheap so you can set out as many as you like around your house without going broke doing it.
The best places to put them are near the windows and doors where the beetles will be most likely to enter your house. If you have any potted plants in your house, put the glue board near them since Japanese beetles will inevitably be attracted to them.
Glue boards are safe, but they are sticky. If your pet rolls on one or plays with it, getting it off their fur will be quite a challenge. The same thing goes for small babies and toddlers. Keep the glue boards out of their reach.
Getting Rid of Japanese Beetles From Your Property Completely
Milky spore disease is a long-term method of killing Japanese beetle larva in the ground. Milky spore, originally Bacillus popilliae, but now known as Paenibacillus popillae, is a bacteria that is only effective against Japanese beetles.
The bacterium is added to the ground as a dust. As the white grubs move through the ground they ingest the spores which begin to reproduce inside the grubs and eventually kill them.
However, ingestion of the milky spores doesn’t always lead to an infection. There is a chance that the spores will simply pass through them and be discharged in their fecal droppings. For this reason, it is required to spread the milky spores over the entire yard.
A 20-pound bag of milky spores will cover 7000 square feet of your yard and/or garden. You’ll need to use a spreader to distribute the milky spores evenly across the ground. Once the spores are in the ground, they’ll last 15-20 years.
Once the milky spores have been added to the yard, it will take at least a year before you start seeing any noticeable results, so be patient.
One of those results will be a gradual shrinking of the brown spots in the yard. Another result will be a decrease in the number of adult Japanese beetles attacking your plants and trees.
They enter the grub through any bodily opening then release a bacteria into the grub’s bloodstream. The bacteria multiply and eventually kill the grubs. The nematodes then feed on the dead grub until it is gone. After that, they go off in search of more grubs.
There are a couple of things to be aware of when using nematodes. First, they are living beings so you need to get them into the ground as quickly as possible before they die in the package. Always check the expiration date on the package, otherwise, you’ll wind up paying for dead nematodes.
Second, nematodes need moisture to thrive. It’s best to put them out after it rains. If you’re in a dry area, water the yard or garden where you’ve used them. Keep the ground moist by watering it at least once every 10 days.
This method works quicker than the milky spores but you’ll have to reapply it every 2-3 weeks until the white grubs are gone. You’ll know they are gone because you won’t see any adult Japanese beetles coming up in your yard the next year in the spring.
This is a chemical insecticidal treatment for the yard. The active ingredient is chlorantraniliprole, an insecticide that consistently reduces white grubs in the ground by up to 65%. It isn’t as water-soluble as some other insecticides so you’ll have to mix it vigorously.
This pesticide won’t hurt earthworms, children, or pets but the one limitation it does have is that it shouldn’t be used in your garden. The chemical will adhere to the plants and you’ll ingest it when you eat them.
It’s easy to apply, just put it in a spreader and begin spreading it over your yard. Each bag will cover about 10,000 square feet, so a little goes a long way.
Pre-made row covers, plastic sheets draped over a frame, can protect your garden plants from adult Japanese beetles. Each one creates a hothouse setup over each row in your garden, giving you a double benefit.
Close the end of each row cover before you go to bed at night, then wait until 10 o’clock or so when the sun is up and hot. Since Japanese beetles are most active early in the morning, they won’t be around by the time you open up the cover to let in some fresh air.
If they can’t find something to eat, they’ll have to go elsewhere to find it or risk starvation.
If you can’t use row covers for things such as rose bushes and fruit trees, you’ll have to do some hand picking to get them off. They can be handled without harm, it just takes a while.
Best Products for Getting Rid of Japanese Beetles
How to Prevent Japanese Beetles in the First Place
Preventing Japanese beetles is best done through the use of Milky Spore Grub Control. If you maintain a constant population of milky spores in the ground around your house, you won’t have to worry about an infestation.
Wrapping It Up
Japanese beetles are more than merely a nuisance. They are a genuine pest that causes untold millions of dollars of damage every year to crops and yards all over the United States. Due to the lack of natural predators, they spread very rapidly.Killing them in your yard and garden not only protects you, but it also protects your neighbors from being infected by them as well. Now that is being a good neighbor!
Other Pest Guides
Curious about other beetle-related articles? Check out our other detailed guides to help you deal with your pest problems.